1. Field
Aspects of embodiments of the present invention relate to a rechargeable battery.
2. Description of the Related Art
A rechargeable battery can repetitively perform charge and discharge, unlike a primary battery. A small-capacity rechargeable battery is commonly used with a portable compact electronic device, such as a mobile phone, a laptop computer, or a camcorder, and a large-capacity rechargeable battery is widely used as a motor-driving power supply, such as for driving a motor of a hybrid vehicle or an electric vehicle.
Recently, a high-power rechargeable battery using a non-aqueous electrolyte having a high energy density has been developed. The high-power rechargeable battery is configured by connecting a plurality of rechargeable batteries in series and may be used for devices requiring a large amount of power, such as a motor drive of an electric vehicle and the like.
The rechargeable battery includes an electrode assembly including a positive electrode and a negative electrode at both sides of a separator, a case housing the electrode assembly, a cap plate sealing an opening of the case, and electrode terminals installed through the cap plate to be electrically connected to the electrode assembly.
Since charging and discharging are repeated in the rechargeable battery, excessive heat may be generated from the inside of the case, or an electrolyte solution may be decomposed. The heat generation or decomposition of the electrolyte solution may cause the internal pressure of the rechargeable battery to be increased. The increase in internal pressure may cause the rechargeable battery to ignite or explode.
In order to prevent fire and/or explosion caused by the increase in internal pressure, an external short-circuit part may be provided outside the case. The external short-circuit part short circuits the negative electrode and the positive electrode of the electrode assembly with each other outside the rechargeable battery when the internal pressure of the rechargeable battery increases. When the external short-circuit part performs a short circuit operation, a charging state of the electrode assembly is decreased due to discharge of a large current. A weak part of a discharge line connecting the electrode assembly and the electrode terminal may be melted and broken due to the discharge of the large current.
In order to effectively disconnect the discharge line in an external short circuit or overcharge, a fuse part may be provided at a lead tab connecting the electrode terminal and the electrode assembly in the rechargeable battery. However, the fuse part is melted and broken and thereafter, when a broken portion is small, an arc may be generated at the broken portion.
An arc generated in the rechargeable battery may act on the electrolyte solution to cause fire or explosion, thereby deteriorating stability of the rechargeable battery.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.